JPH0996417A - Control device for hot water supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a proper amount of combustion even when a combustion rate is limited by providing a heat quantity arithmetic operation unit which transmits a control signal which is equivalent to a heat quantity limited to an approximate value of a theoretical heat quantity within an effective heating value when the theoretical heat quantity exceeds the range of the effective heat quantity which is actually combustible. SOLUTION: A heat quantity arithmetic operation unit 41 compares the output of a theoretical heat quantity arithmetic operation unit 37 with the output of an effective heat quantity 39 and transmits directly the output of the theoretical heating value arithmetic operation unit if it is within the range of the effective heat quantity 39 to an on/off valve drive unit 43 and a proportional valve drive unit 45 and transmits a signal equivalent to the heat quantity limited to the approximate value of the theoretical heat quantity within the range of the output of the effective heat quantity 39 to the on/off valve drive unit 43 and the proportional valve drive unit 45 when the output is out of the range and provides an heat value which is to be originally provided. A required heat quantity arithmetic operation unit 33 outputs output-start time of the amount of correction computed with a required heat quantity correction unit 35 after the elapsed time of the specified time which takes the limitation of the heat quantity in consideration. The limited fuel control variable can be corrected by outputting the corrected amount in the mean time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater controller.

[0002]

2. Description of the Related Art Conventionally, there has been a method of controlling combustion by calculating a theoretical amount of heat based on the amount of water flowing through a heat exchanger, the temperature of entering water, the set temperature and the like.

[0003]

However, in the conventional hot water supply controller, when the combustion operation, the ignition operation such as the burner switching operation, or the vicinity of the maximum load combustion amount or the minimum load combustion amount of the water heater is performed. When burning, the amount of combustion that should be given is limited, and the amount of correction that should be corrected is deviated, and it is not possible to reduce the fluctuation of the tap water temperature due to the change in the required amount of combustion. There was a problem of being lost.

That is, as shown in FIG. 2, although a predetermined ignition operation is performed at the start of combustion, the actual ignition operation is performed as shown in FIG. The combustion control amount in the solid line is limited, and the combustion control amount in the shaded portion is limited.

Further, as in the case of starting the combustion, a predetermined ignition operation is performed during the burner switching operation, so that the combustion control amount is limited, and the combustion control amount is limited as described above.

5 and 6 are graphs showing a state in which the combustion control amount in the vicinity of the minimum load combustion amount and the maximum load combustion amount of the water heater is limited. If the combustion control amount to be originally given exceeds the minimum load combustion amount or the maximum load combustion amount of the water heater, the combustion control amount in the shaded areas in FIGS. 5 and 6 is limited.

Therefore, an object of the present invention is to provide an appropriate combustion amount by supplementing the limited combustion control amount even when the combustion control amount is limited.

[0008]

SUMMARY OF THE INVENTION The present invention is a combustion apparatus provided with a theoretical calorific value calculation unit for calculating a theoretical calorific value required to bring a hot water temperature to a set temperature, and the theoretical calorific value is effective for actual combustion. When exceeding the range of the amount of heat, a calorie calculator is provided for transmitting to the heating unit a control signal corresponding to the amount of heat limited to the approximate value of the theoretical amount of heat within the range of the effective amount of heat.

Further, the theoretical calorific value calculating section calculates the necessary calorific value from the quantity of water flowing through the heat exchanger, the incoming water temperature, and the set temperature, and the required calorific value by detecting a sudden change in the necessary calorific value. It is characterized in that the theoretical calorific value is calculated according to an input signal of a necessary calorific value correction unit for correction.

According to one preferred embodiment of the first aspect of the present invention, the theoretical calorific value calculating section calculates a necessary calorific value based on the quantity of water flowing through the heat exchanger, the incoming water temperature and the set temperature. To provide an appropriate amount of combustion even when it is highly likely that the heat quantity is limited in the case of a quantity calculation section and a necessary heat quantity correction section that detects the sudden change in the necessary heat quantity and corrects the necessary heat quantity It is possible to quickly bring the hot water outlet temperature close to the set temperature.

Further, in a preferred embodiment according to the first aspect of the present invention, the calorific value calculation unit determines the generated calorific value associated with the switching of a plurality of burners or the maximum load calorific value or the minimum load calorific value of the heating unit. It is characterized in that it is within the range of effective heat quantity.

Further, the calorific value calculating section uses the maximum calorific value or the minimum calorific value of the heating section as an approximate value.

According to the present invention, when the theoretical calorific value exceeds the range of the effective calorific value that can be actually burned, the control signal corresponding to the calorific value limited to the approximate value of the theoretical calorific value is heated within the effective calorific value range. Since it has a calorific value calculation unit to send to
Even if the amount of combustion is limited, an appropriate amount of combustion can be given, and the tap water temperature can quickly approach the set temperature.

Further, the theoretical calorific value calculating section calculates a necessary calorific value from the quantity of water flowing through the heat exchanger, the incoming water temperature and the set temperature, and the required calorific value by detecting a sudden change in the necessary calorific value. Even when the necessary heat amount correction unit for correction is used and the heat amount is particularly likely to be limited, an appropriate combustion amount can be given, and the outlet heated water temperature can quickly approach the set temperature. According to one preferred embodiment of the first aspect of the present invention, the amount of heat is limited when the amount of heat is limited by ignition operation or when the amount of heat exceeds the maximum load combustion amount or the minimum load combustion amount of the water heater. Even if the temperature is limited, an appropriate amount of combustion can be given, so that the hot water outlet temperature can quickly approach the set temperature. Furthermore, by using the maximum heat amount or the minimum heat amount of the heating section as the approximate value, the tapping temperature can be brought closer to the set temperature even more quickly.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic configuration of a main part of a hot water supply apparatus according to an embodiment of the present invention, in which a temperature of water supplied from the water inlet 2 is provided in a hot water supply channel connecting the water inlet 2 and the outlet 4. An inlet water temperature detection sensor 21 for detecting the flow rate and a flow rate sensor 25 for detecting the amount of water flowing through the heat exchanger 17 are provided.

The burner 1, which heats the heat exchanger 17,
3 has a two-stage burner, and these two burners 1, 3
On-off valves 9 and 11 are provided in the branched fuel supply pipes 5 and 7, respectively.
A proportional valve 15 for fuel adjustment is provided in the original fuel pipe 13 from which the fuel supply pipes 5, 7 are branched. A fan 29 is provided near the burners 1 and 3 to supply the air required for burning the burners 1 and 3.

As shown in the block diagram of FIG. 9, the control device 31 includes a required heat quantity calculating section 33, a necessary heat quantity correcting section 35, a theoretical heat quantity calculating section 37, an effective heat quantity 39, a heat quantity calculating section 41, an on-off valve driving section 43 and a proportional quantity. The valve drive unit 45 is provided.

10 and 11 are views showing the display mode when the temperature setting device 51 is in an abnormal state. If there is a possibility that hot water will come out, it will be forced to 75 ℃ as shown in Fig. 10.
May be displayed, or the LED may be turned on as shown in FIG.

The required heat amount calculation unit 33 calculates the required heat amount F calculated by the following equation based on the incoming water temperature Tc, the flow rate Q and the set temperature Ts from the temperature setter 51, and uses this to calculate the required heat amount correction unit. 35 and the theoretical calorific value calculation unit 37. F = Qx (Ts-Tc)

The required heat amount correction unit 35 is configured to output a correction amount αF with respect to the required heat amount F. For example, a correction amount αF calculated by the following equation from the rate of change of the required heat amount F and the gain coefficient K is used. It is calculated and sent to the combustion amount control unit 34 for a predetermined time T considering the response time of the heat exchanger 17. αF = K × (F−F ′) / F ′ Here, F ′ is the required heat quantity before a predetermined time (for example, about 1 to 3 seconds). The gain coefficient K may be variable according to the combustion time from the start of combustion.

The theoretical calorific value calculation unit 37 inputs the necessary calorific value F and the correction amount αF, corrects the necessary calorific value F by the correction amount αF,
It is output as the combustion control amount FOUT calculated by the following equation. FOUT = F × αF

The on-off valve drive unit 43 controls the combustion control amount FOUT.
Is operated in advance when the minimum ignition combustion amount, which is the ignition condition of the first burner 1 stored in advance, and the flow rate Q exceeds the minimum ignition flow rate, a signal is sent to the first on-off valve 9 and the first burner 1
Light up. After the ignition, when the combustion control amount FOUT exceeds the pre-stored ignition transfer amount, which is the ignition condition of the second burner 3, a signal is sent to the second on-off valve 11 to ignite the second burner 3.

The proportional valve drive unit 45 controls the combustion control amount FOUT.
A signal for controlling the opening of the proportional valve 15 according to the above is output to the proportional valve 15.

The calorific value calculation unit 41 compares the output of the theoretical calorific value calculation unit 37 with the output of the effective calorific value 39, and if the output is within the range of the effective calorific value 39, the output of the theoretical calorific value calculation unit 37 is directly proportional to the on-off valve drive unit 43 and the proportional valve. The valve drive unit 45 transmits. When the output of the theoretical calorific value calculation unit 37 is outside the output range of the effective calorific value 39, a signal corresponding to the calorific value limited to the approximate value of the theoretical calorific value within the output range of the effective calorific value 39 is output to the on-off valve drive unit 43 and the proportional value. The heat quantity indicated by the solid line in FIG. 3 is obtained by the transmission of the valve drive unit 45, and the heat quantity that should be given can be given. Further, as a signal corresponding to the heat quantity limited to the approximate value of the theoretical heat quantity, a gain coefficient K1 having a value larger than the gain coefficient K is obtained.
May be output to the heat quantity calculation unit 41. By using this gain coefficient K1, it becomes possible to give the combustion control amount that should be given. Further, the required heat amount calculation unit 35 outputs the correction start amount output time of the correction amount αF calculated by the required heat amount correction unit 35 after a lapse of a predetermined time in consideration of the limitation of the heat amount. Correction amount αF during this time T1
By outputting, the combustion control amount as shown by the solid line in FIG. 4 is given, and the limited combustion control amount is supplemented.

As the effective heat quantity 39, theoretically and experimentally obtained heat quantities that can be given to the water flowing through the heat exchanger can be stored in a table format, and in the present embodiment, a predetermined time T1 considering that the heat quantity is limited. Alternatively, the maximum load heat amount or the minimum load heat amount of the heating unit is set from the outside. The stored contents are read out by the calorific value calculation unit 41, and the theoretical calorific value FO
The heating unit is actually driven by comparing the UT and the read contents appropriately. For example, the theoretical heat quantity FOUT is compared with the read maximum load combustion quantity FMAX, and FOUT is FMAX.
When the value exceeds, the heating unit is driven by the control signal corresponding to the heat quantity limited to the approximate value of the theoretical heat quantity. Similarly, theoretical heat FO
Compare the UT and the read minimum load combustion amount FMIN,
When FOUT becomes equal to or lower than FMIN, the heating unit is driven by the control signal corresponding to the heat quantity limited to the approximate value of the theoretical heat quantity. Therefore, the combustion control amount shown by the solid lines in FIGS. 7 and 8 is given, and the limited combustion control amount can be supplemented.

In still another embodiment, the calorific value calculation unit can quickly bring the hot water outlet temperature close to the set temperature by using the maximum calorific value or the minimum calorific value of the heating unit as an approximate value.

[0028]

As described above, according to the controller of the hot water supply apparatus of the present invention, at the start of combustion, the ignition operation such as the burner switching operation, and the vicinity of the maximum load combustion amount and the minimum load combustion amount of the water heater. When burning, etc., when the amount of heat that must be given is limited and the amount of correction that should be corrected deviates, it is necessary to supplement the limited amount of correction. Disturbances in the tap water temperature due to changes in the amount of combustion can be reduced, and the tap water temperature can be brought closer to the set temperature quickly.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of a hot water supply device to which the present invention is applied

FIG. 2 is a graph showing a limited amount of heat at the start of combustion.

FIG. 3 is a graph showing the amount of heat generated at the start of combustion in the same embodiment.

FIG. 4 is a graph showing a limited amount of heat when switching burners.

FIG. 5 is a graph showing the heat quantity restricted near the minimum load combustion quantity.

FIG. 6 is a graph showing the heat quantity restricted near the maximum load combustion quantity.

FIG. 7 is a graph showing the amount of heat generated near the minimum load combustion amount in the same embodiment.

FIG. 8 is a graph showing the amount of heat generated near the maximum load combustion amount in the same embodiment.

FIG. 9 is a control block diagram in the control device in the embodiment.

FIG. 10 is a display form of a display unit when the temperature setting device is in an abnormal state in the same embodiment.

FIG. 11 is a display form of a display unit when the temperature setting device is in an abnormal state in the same embodiment.

[Explanation of symbols]

 1, 3 Burner 2 Inlet port 4 Outlet port 5,7 Fuel supply pipe 9,11 Open / close valve 13 Main fuel pipe 15 Proportional valve 17 Heat exchanger 21 Inlet water temperature detection sensor 25 Flow rate sensor 29 Fan 31 Controller 51 Temperature setter

Claims (4)

[Claims] 1. A combustion apparatus equipped with a theoretical calorific value calculation unit for calculating a theoretical calorific value required to bring a hot water temperature to a set temperature, when the theoretical calorific value exceeds an effective calorific value range in which actual combustion is possible, A controller for a water heater, comprising a calorie calculator for transmitting a control signal corresponding to a calorie limited to an approximate value of the theoretical calorie within a range of the effective calorie to a heating part. 2. The control device for a water heater according to claim 1, wherein the theoretical calorific value calculation unit includes a necessary combustion amount calculation unit that calculates a necessary heat amount from the amount of water flowing through the heat exchanger, the incoming water temperature and the set temperature. A controller for a water heater, wherein the theoretical heat quantity is calculated by an input signal of a necessary heat quantity correction unit that detects a sudden change in the necessary heat quantity and corrects the necessary heat quantity. 3. The hot water supply controller according to claim 1, wherein the calorific value calculation unit sets a heat amount generated by switching of a plurality of burners or a maximum load heat amount or a minimum load heat amount of the heating unit to a range of the effective heat amount. A controller for a water heater, which is characterized by: 4. The water heater control device according to claim 1, wherein the heat amount calculation unit uses the maximum heat amount or the minimum heat amount of the heating unit as an approximate value.